go/doc: lineWrapper does not add // prefix while wrapping a line comment

[rsc]

$ go doc csv.Reader.ReuseRecord
struct Reader {
    // ReuseRecord controls whether calls to Read may return a slice sharing
    // the backing array of the previous call's returned slice for performance.
    // By default, each call to Read returns newly allocated memory owned by the
    caller.
    ReuseRecord bool
}

Note the "caller" line without a leading //. It should have one.

/cc @robpike

[robpike]

Pretty sure this is a bug in go/doc's ToText function. cmd/doc calls that to format comments.

[bradfitz]

@griesemer?

[bradfitz]

Hard to see this as a release blocker, though. Demoting to Maybe.